The present invention relates generally to shipping/storage racks. More particularly, the present invention relates to a rack with a torsionally loaded shelf.
Typically, in order to satisfy ergonomic regulations, certain racks include a pair of gas-shocks that biases upward movement of a manually pivotable shelf from a stowed position (i.e. a down position) to a deployed position (i.e. an up position). Essentially, the gas-shocks reduce the amount of effort needed by an operator to lift a heavy pivotable shelf on the rack from the stowed position to the deployed position.
Although adequate for most applications, the gas-shocks are a high-maintenance item that are sensitive to damaging side-impacts. Even further, the gas-shocks typically comprise a nitrogen-charged cylinder that may fail in a number of different ways. For example, the gas-shocks are very temperature-sensitive; if the rack is moved from a cold environment to a warm environment and the gas-shocks are activated without allowing appropriate time to adjust to the new temperature, the gas-shocks may rupture and fail upon activation. Yet even further, the gas-shocks are typically exposed to a gritty, grimy atmosphere in an industrial environment; as a wiper-seal of the respective gas-shocks reciprocates back and forth over the gas-shock""s shaft portion, the gas-shocks may become contaminated with abrasives that may compromise the integrity of the gas-shock""s wiper-seal, resulting in their undesirable failure.
As a result of the drawbacks associated with conventional gas-shocks that biases upward movement of a rack""s pivotable shelf, it is apparent that there is a need for a device that improves upward biasing arrangements of racks.
In a first embodiment of the invention, a rack is described. The rack comprises at least one pivotable shelf. The pivotable shelf is adapted to conform to one or more component parts. The pivotable shelf comprises an upward biasing arrangement. The upward biasing arrangement includes a spring actuated device that biases upward movement of the pivotable shelf.
A second embodiment of the invention is a rack. In this embodiment, the first and second adjusting mechanisms further comprise an inner cup and an outer cup, respectively. The first and second torsion bars include a first and second end. The first torsion bar extends from a first corner post at its first end to a first receiving portion of a rear arm at its second end, and the second torsion bar extends from a second corner post at its first end to a second receiving portion of the rear arm at its second end. The first and second torsion bars are rigidly fastened, at both of their first and second ends, to the first and second receiving portions and the corner posts, respectively. The first and second torsion bars are welded to the first and second adjusting mechanisms, respectively, that are located at the first and second corner posts, respectively. The outer cup of the first and second adjusting mechanisms includes an opening that allows passage of the first and second torsion bars, respectively, for termination at the inner cup of the first and second adjusting mechanisms, respectively. The first and second torsion bars are welded to the inner cup of the first and second adjusting mechanisms, respectively. The outer cup of the first and second adjusting mechanisms are welded to one the first and second corner posts, respectively, and the inner cup of the first and second adjusting mechanisms are free to rotate within the outer cup of the first and second adjusting mechanisms, respectively. The inner cup of the first and second adjusting mechanisms includes torquing tool receiving passages that extend through the inner cup of the first and second adjusting mechanisms such that a torquing tool can be matingly received at the torquing tool receiving passages for the purpose of rotating the inner cup of the first and second adjusting mechanisms in order to pre-torque the first and second torsion bars, respectively. The outer cup of the first and second adjusting mechanisms comprises a first pin receiving passage, and the inner cup of the first and second adjusting mechanisms comprises a plurality of second pin receiving passages.
The second embodiment of the invention also comprises a first and second locking pin. The first and second locking pins are passed, respectively, through the first pin receiving passage and then through one of a plurality of second pin receiving passages in the outer cup and inner cup, respectively, in order to prevent any relative movement between the inner cup and the outer cup of the first and second adjusting mechanisms, respectively.
Another embodiment of the invention is a rack. In this embodiment, the rack comprises means for adjusting torque and means for biasing upward movement of a pivotable shelf. The means for adjusting torque is a pair of adjusting mechanisms. The means for biasing upward movement of a pivotable shelf is a pair of torsion bars made from spring steel.
Various additional aspects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.